1. Field of the Invention
This invention relates to release mechanisms for securing and quickly releasing tow boats and tugs from one or a string of barges, as well as boats and ships from docks. More particularly, the invention relates to a remote controlled, air or hydraulically operated, portable cable release mechanism which improves the conventional pelican hook release devices currently in use and is sufficiently versatile to be used not only on tow boats but also on docks and ships as well. In a typical river barge towing arrangement according to this invention, the tow boat is connected to a string of barges by means of steel tow cables which may be as large as 11/4 inches or fiber rope cables as large as 3 inches in diameter. The tow cables are typically looped through a pelican hook and keeper ring device mounted on or secured to the deck of the tow boat and then around the tow boat and barge deck fittings, to one or more winches for adjusting the distance between the lead barge or barges and the tow boat. The end of each towing cable which is attached to a pelican hook is typically provided with a loop which fits around the neck of the pelican hook near the point of pivot of the pelican hook in the base. The free end of the pelican hook is then pivoted downwardly and forwardly while the cable is slack, to facilitate manipulation of a keeper ring, which is slidably attached to the base, over the end of the pelican hook. The keeper ring thus deployed prevents the pelican hook from pivoting rearwardly on its hinges and releasing each cable loop when tension is placed on the cables by the winch. The barges are then manipulated into alignment with the tow boat and are maintained in this orientation while the barges are being towed. Accordingly, in the event of an emergency which requires release of the barges from the tow boat, the keeper ring can be removed by remote control from the end of the pelican hook, or it can be manually removed by means of a sledge hammer, pry bar or screwdriver during the towing operation.
Conventional docking techniques using cables and ropes depend upon careful orchestration of all lines by deckhands and dock crews to prevent damage to the dock and/or the ship or vessel. The cable release mechanism of this invention can be mounted on a dock or ship to secure the ship to a dock and release the ship from the dock in a uniform and efficient manner.
2. Description of the Prior Art
A cable release mechanism for mounting on a tow boat and securing a string of barges in towing configuration is disclosed in my U.S. Pat. No. 4,540,210, dated Sept. 10, 1985. Conventional pelican hook cable retaining mechanisms have long been used on tow boats to releasably secure towing cables to barges and are generally characterized by an elongated pelican hook which is pivotally attached to a pair of hinges welded to a base plate or to the deck of a tow boat. The base plate is in turn bolted or otherwise secured to the deck of the tow boat and a keeper ring is loosely mounted on a keeper ring stay, which is also welded or otherwise attached to the base or tow boat deck adjacent the free end of the pelican hook. Accordingly, the keeper ring is slipped over the end of the pelican hook when the pelican hook is rotated downwardly on the hinges to secure the cable loop of a towing cable between the pelican hook and the base plate or tow boat deck. The keeper ring can be quickly removed from the end of the pelican hook during the towing operation by sharply striking it or prying it to release the cable loop and cable. A disadvantage of manually releasing the keeper ring from the end of the pelican hook in this manner is found in the large amount of stress which is placed on the pelican hook and the keeper ring during towing of a barge or barges. The rearward force on the pelican hook assembly due to the weight of the barge or barges and the force of the tow boat pulling the barge string causes the pelican hook to press tightly against the keeper ring. Accordingly, considerable force is often required to dislodge the keeper ring from the end of the pelican hook. Accomplishing this act with the aid of a sledge hammer or pry bar has resulted in injury to the operator, since the force of the pelican hook rapidly pivoting upwardly and rearwardly after the keeper ring is dislodged under towing conditions has, on occasion, knocked the sledge hammer or pry bar completely out of the hands of the operator. Another disadvantage of the conventional pelican hook is the typically narrow deck or cable-bearing area, which frequently causes flattening and sometimes failure of the cable due to the large stresses applied to the cable.
As noted above, a cable release mechanism for mounting on the deck of a tow boat, tug or other vessel for towing barges is disclosed in my U.S. Pat. No. 4,540,210 dated Sept. 10, 1985. Other patents pertinent to the subject matter of this patent are noted as patent references of record in that patent.
Yet another problem associated with prior art remote control release mechanisms is the complexity of such devices, a factor which sometimes results in malfunction of the devices due to the relative large number of parts which must interact in a certain way to achieve the desired result. Furthermore, as heretofore described, conventional manually operated pelican hook and keeper ring cable stay devices are dangerous to trip and require an operator to be in a hazardous position in an emergency. Accordingly, it is an object of this invention to provide a new and improved portable pelican hook cable release mechanism which is simple in design, easy to operate from a safe and remote location on the boat, ship or dock. The cable release mechanism includes an improved pivoting pelican hook and positive keeper assembly provided in cooperation with a fluid activated cylinder, to selectively engage and secure a tow cable during barge towing operations and a ship or boat during docking operations and to quickly, easily and remotely or manually release the tow cable or dock cable from the cable release mechanism in the event of an emergency or during normal operation.
Another object of this invention is to provide a new and improved, portable remote control or manual cable release mechanism of the pelican hook and keeper design for securing and selective releasing a tow cable from a tow boat and docking cables from ships and other vessels. The cable release mechanism includes a pelican hook assembly fitted with a hydraulic or air cylinder and a sliding keeper attached to the cylinder piston, which keeper is provided in normally engaged position on the end of the pelican hook during the towing or docking operation and is operationally displaced from the end of the pelican hook in remote control mode by activation of the air or hydraulic cylinder. Extension of the cylinder piston in manual mode is effected by manipulation of a lanyard cable to remove the keeper from contact with the pelican hook.
A still further object of the invention is to provide an improved remote control or manually operated, portable pelican hook and keeper cable release mechanism which can be removably mounted to the deck of a tow boat and utilized in cooperation with a standard winch system on the tow boat to releasably secure one end of a tow cable and bind a barge string to the tow boat. The cable release mechanism is characterized by a pelican hook pivotally mounted on a hinge or hinges attached to a frame and a cooperating keeper attached to the piston of a hydraulic or air cylinder also mounted on the frame, which cylinder can be activated to extend the cylinder piston with respect to the frame and remove the keeper from contact with the pelican hook in automatic operation. The keeper can be manually slidably adjusted from the end of the pelican hook by operation of a lanyard cable in an emergency situation to release the tow cable from the pelican hook and the tow boat.
Yet another object of this invention is to provide an improved automatic or manual cable release mechanism incorporating a pelican hook and a keeper assembly, which mechanism can be removably mounted on the deck of a tow boat or on a dock for securing the looped end of a tow cable or dock cable to the pelican hook and removably securing the pelican hook in folded, closed position by means of a keeper which is mounted on the end of a piston carried by an air or hydraulic cylinder. The air or hydraulic cylinder is provided with a solenoid valve and appropriate remote controls, in order to facilitate remote activation of the air or hydraulic cylinder and extension of the cylinder piston in remote control operation. Manual extension of the keeper from the pelican hook can also be facilitated by operation of a lanyard cable, to release the cable under towing or docking conditions.